Aircraft wheels are known that include a rim and a tire received on the rim, the rim comprising two rim halves that are assembled together by means of bolts that are regularly spaced apart.
Each rim half, which is made of an aluminum alloy, conventionally has a bearing surface that extends in a plane perpendicular to an axis of rotation of the wheel. When the rim is assembled, the bearing surfaces of the rim halves are positioned one against the other. Each rim half then exerts considerable compression on the bearing surface of the other rim half. As a result of this considerable compression, the coefficient of friction between the bearing surfaces is high.
However, while the wheel is rotating, the various peripheral zones of the tire and of the rim are subjected to loading and to rest in alternation. Under such circumstances, the rim halves are then subjected to radial and peripheral micro-movements relative to each other, which micro-movements can be considered as creeping motion.
The coefficient of friction between the bearing surfaces of the rim halves is such that the radial and peripheral micro-movements lead to a protective coating on the bearing surfaces becoming torn off progressively. The bare aluminum bearing surfaces are then subjected to a phenomenon of fretting under tension, which damages the bare bearing surfaces and leads to cracks being formed.
Thus, when changing a tire, it is often necessary either to rework the bare bearing surfaces by machining and to reapply the protective coating, or else, in the event that it is observed that cracking has started, to replace the rim half in question since it is no longer reusable. The maintenance costs associated with these operations are relatively high.